Application Note
DASDEC™ Digital Audio Insertion with BDI AES-302
Introduction
The DASDEC EAS Encoder/Decoder is controlled via a web browser over a LAN or by using a connected
keyboard/monitor/mouse and the built-in desktop browser interface. The unit has 3 built-in radios for FM/AM/NOAA
reception. It also has a fourth analog audio decoder input that can be connected to an external receiver. The
DASDEC offers both traditional analog Emergency Alert System (EAS) and digital EAS via serial and LAN control
protocols, with MPEG streaming, AES audio output and using third party equipment. The DASDEC can be interfaced
to the Broadcast Devices, Inc AES-302 Digital Audio System to reliably insert EAS audio into an AES program
stream.
Digital Audio Insertion
The DASDEC with AES option provides a single balanced AES digital audio output for Emergency Alert System
audio. The DASDEC does NOT offer a built-in pass-through feature for digital audio. Rather, the DASDEC can be
easily interfaced to other platforms built especially for robust digital audio switching and insertion. The Broadcast
Devices, Inc AES-302 Digital Audio System is a Digital Alert Systems recommended 1RU platform for achieving EAS
audio insertion into an existing AES program stream. This unit offers fail-safe pass-through of the main input AES
program stream even when power is removed from the platform. The unit also is a 4-channel digital distribution
amplifier providing 4 AES outputs from the selected input. It also has a digital to balanced analog converter, providing
a fifth output channel.
Interfacing a DASDEC to the AES-302 is simple. Your station provides the main on-air AES audio to channel A of the
AES-302. The DASDEC provides other digital audio input to channel B of the AES-302. During an EAS alert event,
the DASDEC provides EAS audio out of its AES and analog audio output ports. Through the use of two GPI output
relays from the DASDEC, the AES-302 unit is switched between program audio to alert audio during an EAS
origination or forwarding event. It is then switched back to program audio at the end of the alert notification. See
Diagram 1. The AES-302 also features manual override switches to easily switch from the DASDEC audio channel B
back to the program channel A.
System Integration
Audio Connection:
Connect the DASDEC AES card digital breakout XLR cable for AES output to input channel B on the back
of the AES-302. Connect your program audio via XLR to channel A of the AES-302. Connect the XLR
connector for your main AES program output to the Output 1 on the back of the AES-302. Connect
duplicate outputs to the any of AES output 2 through 4.
GPI Connection option 1:
The two built-in DASDEC relays can be used to trigger switching during alert activation. Connect one line
of the DASDEC relay 1 to the AES-302 DB9 control port input pin 9 and the other line to pin 3. Connect
one line from the DASDEC relay 2 to the AES-302 DB9 control port input pin 9 and the other to pin 4. See
Table 1 for AES-302 pinout. DASDEC GPI output relay one will provide the switch at the start of EAS
audio to AES channel B. Login to the DASDEC Web browser and go to Setup->GPIO. Set the second GPI
Ouput relay to the setting to close “Momentarily at end of EAS Audio Playout”. This will provide the
switch back to the program audio on channel A.
GPI Connection option 2:
The DASDEC NET-GPIO option relays can be also used to trigger switching during alert activation. Use
this option if the back panel relays are already used or if the AES-302 cannot be rack mounted close to
the DASDEC. This option requires a valid network connection from the DASDEC, the Titus Technologies
WebREM-300 hardware or the Monroe Electronics R190 rack unit hardware, and programming of a
DASDEC NET GPIO client interface. The NET GPIO client interface (in DASDEC Web browser under
Digital Alert Systems
A division of Monroe Electronics
585-765-1155 | fax 585-765-9330
100 Housel Ave. | Lyndonville | NY | 14098
www.digitalalertsystems.com
Revision: 1 Publication: APNDAS-0101
Copyright © 2009-2010 Digital Alert Systems, a division of Monroe Electronics Inc.
Information herein is considered accurate at the time of publication. We constantly strive to
improve our products and services therefore some specifications are subject to change
without notice. DASDEC, MultiStation, and EAS-Net are trademarks of Digital Alert
Systems and Monroe Electronics.
Digital Alert Systems
Application Note
Setup->Net Alerts->Net GPIO) provides a variety of trigger options for each of the four relays provided per
unit. You simply program one of the relays to momentarily close at the start of EAS Audio and another to
momentarily close at the end of EAS audio. Wire the relay outputs to the appropriate pins on the AES302. See Table 2 for WebREM-300/Monroe R190 pinout. Do not forget to program the IP address of the
WebREM-300 and set the address under the NET GPIO client interface.
AES audio output XLR connected to
back of AES-302 input channel B.
DASDEC-1EN
EAS
Alert Orig/Forward
DASDEC EAS Audio
GPI Relay 1: Causes
switch to input channel
B during EAS activation.
A
B
DASDEC programmable GPI
Relay 2: Momentary closure
option causes AES-302 to
switch back to program audio
channel A
BDI AES302
AES Audio Out
Channel 1: Program
audio from Input A
except during EAS
activation from
DASDEC. During
activation audio from
input channel B
Normal Program AES
Audio connected to
back of AES-302 input
channel A.
Analog output
duplicates output 1
AES output 2-4
duplicates output 1
Figure 1 Basic connection diagram for digital audio insertion in to a TV or radio broadcast using DASDEC and BDI-302.
PIN #
FUNCTION
1
2
3
4
5
6
7
8
9
+15 VDC @ 100mA.
No connection
Select channel B input
Select channel A input
Error Reset
Status relay common
Status - “B” selected
Status - “A” selected
Ground
Command input pins 3, 4, and 5 requires a momentary closure to ground.
However, constant closure to ground will also switch from channel A to B.
This allows DASDEC Relay 1 to be used to switch from program audio on
channel A to EAS audio on channel B. The status connections are to dry
contacts. Use no more than 24VDC on these contacts or damage to the
relay can occur. The DASDEC does not provide any interfaces to the status
connections.
Status input lines are not supported on the DASDEC as of 1. 6-1 software.
Table 1 DB-9 Pinout on AES-302
PIN #
FUNCTION
1
Relay 2 contact
2
3
4
5
6
Relay 1 contact
Relay 4 contact
Relay 3 contact
Relay common and
status input common
Status 2 input
7
8
9
Status 1 input
Status 4 input
Status 3 input
Programmable on DASDEC under
Setup->Net Alerts->Net GPIO
Wire to ground connection.
Unused by DASDEC.
Relay output is normally open and is
rated at 1 Amp @ 5 VDC. The status
inputs are TTL level (5 VDC true). Care
should be taken to not exceed these
ratings.
Status input lines on pin 6-9 are not
supported on the DASDEC as of 1.6-1
software.
Table 2 DB-9 Pinout on Monroe R190 or Titus Technologies WebREM-300
DASDEC™ Digital Audio Insertion with BDI AES-302
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